Server Side Rendering

import { createCache, extractStyle, StyleProvider } from '@ant-design/cssinjs';
import { renderToString } from 'react-dom/server';

export default () => {
  // SSR Render
  const cache = createCache();

  const html = renderToString(
    <StyleProvider cache={cache}>
      <MyApp />
    </StyleProvider>,
  );

  // Grab style from cache
  const styleText = extractStyle(cache);

  // Mix with style
  return `
<!DOCTYPE html>
<html>
  <head>
    ${styleText}
  </head>
  <body>
    <div id="root">${html}</div>
  </body>
</html>
`;
};

npm install ts-node tslib cross-env --save-dev

{
  "compilerOptions": {
    "strictNullChecks": true,
    "module": "NodeNext",
    "jsx": "react",
    "esModuleInterop": true
  },
  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx"]
}

// scripts/genAntdCss.tsx
import fs from 'fs';
import { extractStyle } from '@ant-design/static-style-extract';

const outputPath = './public/antd.min.css';

const css = extractStyle();

fs.writeFileSync(outputPath, css);

import fs from 'fs';
import { extractStyle } from '@ant-design/static-style-extract';
import React from 'react';
import { ConfigProvider } from 'antd';

const outputPath = './public/antd.min.css';

const testGreenColor = '#008000';
const testRedColor = '#ff0000';

const css = extractStyle((node) => (
  <>
    <ConfigProvider
      theme={{
        token: {
          colorBgBase: testGreenColor,
        },
      }}
    >
      {node}
    </ConfigProvider>
    <ConfigProvider
      theme={{
        token: {
          colorPrimary: testGreenColor,
        },
      }}
    >
      <ConfigProvider
        theme={{
          token: {
            colorBgBase: testRedColor,
          },
        }}
      >
        {node}
      </ConfigProvider>
    </ConfigProvider>
  </>
));

fs.writeFileSync(outputPath, css);

// package.json
{
  "scripts": {
    "dev": "next dev",
    "build": "next build",
    "start": "next start",
    "lint": "next lint",
    "predev": "ts-node --project ./tsconfig.node.json ./scripts/genAntdCss.tsx",
    "prebuild": "cross-env NODE_ENV=production ts-node --project ./tsconfig.node.json ./scripts/genAntdCss.tsx"
  }
}

import { StyleProvider } from '@ant-design/cssinjs';
import type { AppProps } from 'next/app';
import '../public/antd.min.css'; // add this line
import '../styles/globals.css';

export default function App({ Component, pageProps }: AppProps) {
  return (
    <StyleProvider hashPriority="high">
      <Component {...pageProps} />
    </StyleProvider>
  );
}

import { extractStyle } from '@ant-design/static-style-extract';
import { ConfigProvider } from 'antd';

const cssText = extractStyle((node) => (
  <ConfigProvider
    theme={{
      token: {
        colorPrimary: 'red',
      },
    }}
  >
    {node}
  </ConfigProvider>
));

import { extractStyle } from '@ant-design/static-style-extract';
import { ConfigProvider } from 'antd';

const cssText = extractStyle((node) => (
  <>
    <ConfigProvider
      theme={{
        token: {
          colorBgBase: 'green ',
        },
      }}
    >
      {node}
    </ConfigProvider>
    <ConfigProvider
      theme={{
        token: {
          colorPrimary: 'blue',
        },
      }}
    >
      <ConfigProvider
        theme={{
          token: {
            colorBgBase: 'red ',
          },
        }}
      >
        {node}
      </ConfigProvider>
    </ConfigProvider>
  </>
));

// scripts/genAntdCss.tsx
import { createHash } from 'crypto';
import fs from 'fs';
import path from 'path';
import type Entity from '@ant-design/cssinjs/lib/Cache';
import { extractStyle } from '@ant-design/cssinjs';

export type DoExtraStyleOptions = {
  cache: Entity;
  dir?: string;
  baseFileName?: string;
};
export function doExtraStyle({
  cache,
  dir = 'antd-output',
  baseFileName = 'antd.min',
}: DoExtraStyleOptions) {
  const baseDir = path.resolve(__dirname, '../../static/css');

  const outputCssPath = path.join(baseDir, dir);

  if (!fs.existsSync(outputCssPath)) {
    fs.mkdirSync(outputCssPath, { recursive: true });
  }

  const css = extractStyle(cache, true);
  if (!css) return '';

  const md5 = createHash('md5');
  const hash = md5.update(css).digest('hex');
  const fileName = `${baseFileName}.${hash.substring(0, 8)}.css`;
  const fullpath = path.join(outputCssPath, fileName);

  const res = `_next/static/css/${dir}/${fileName}`;

  if (fs.existsSync(fullpath)) return res;

  fs.writeFileSync(fullpath, css);

  return res;
}

// _document.tsx
import { StyleProvider, createCache } from '@ant-design/cssinjs';
import type { DocumentContext } from 'next/document';
import Document, { Head, Html, Main, NextScript } from 'next/document';
import { doExtraStyle } from '../scripts/genAntdCss';

export default class MyDocument extends Document {
  static async getInitialProps(ctx: DocumentContext) {
    const cache = createCache();
    let fileName = '';
    const originalRenderPage = ctx.renderPage;
    ctx.renderPage = () =>
      originalRenderPage({
        enhanceApp: (App) => (props) => (
          <StyleProvider cache={cache}>
            <App {...props} />
          </StyleProvider>
        ),
      });

    const initialProps = await Document.getInitialProps(ctx);
    // 1.1 extract style which had been used
    fileName = doExtraStyle({
      cache,
    });
    return {
      ...initialProps,
      styles: (
        <>
          {initialProps.styles}
          {/* 1.2 inject css */}
          {fileName && <link rel="stylesheet" href={`/${fileName}`} />}
        </>
      ),
    };
  }

  render() {
    return (
      <Html lang="en">
        <Head />
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    );
  }
}

Ant Design

Server Side Rendering

Inline Style

Whole Export

Custom theme

Mixed theme

Extract on demand